In the following essay, Gray asserts that the form and even the ideas of Xenophon 's Defence of Socrates were shaped by rhetorical requirements, specifically the "rule of propriety"—that a speaker's words in a dialogue must be appropriate to his character.

The death of Socrates gave birth to an industry of biographical literature which often took the form of a defence (apologia) or prosecution (kate̵goria), sometimes purporting to be the actual defence or prosecution conducted at his trial. Plato and Xenophon wrote works in his defence. Among his critics, one Polycrates had a certain notoriety. Lysias, Theodectes and Demetrius of Phalerum, orators and rhetoricians like Polycrates, were credited with further works of apology. There were doubtless many others. The aim...